--- title: JavaScript Visualized | daily.dev description: This post explores the inner workings of promises in JavaScript, including the creation of promises using the `new Promise` constructor, the purpose of the... canonical: https://daily.dev/posts/javascript-visualized-jf60glu2w twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: JavaScript Visualized | daily.dev og:description: This post explores the inner workings of promises in JavaScript, including the creation of promises using the `new Promise` constructor, the purpose of the... og:url: https://daily.dev/posts/javascript-visualized-jf60glu2w og:image: https://api.daily.dev/og/posts/Jf60GLU2W.png og:image:alt: JavaScript Visualized og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # JavaScript Visualized **[Community Picks](https://daily.dev/sources/community)** · 6 min read · 2478 upvotes · 47 comments ## Summary This post explores the inner workings of promises in JavaScript, including the creation of promises using the `new Promise` constructor, the purpose of the Promise Reaction record, and how promises can be used to handle asynchronous tasks in a non-blocking way. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@debajyatidey** · 18 upvotes > The blog website has some scrolling issues! :( **@praetoriani** · 12 upvotes > This is a really good post that really explains the topic very well... but there is actually a problem with an asynchronous javascript in the header of the page. This script runs in the background for quite a long time and ends up running into an uncaught promise error. In addition, the site uses a million DIVs, some of which are also animated. And of course that costs a lot of CPU performance. > > Why use a GIF when a few hundred DIVs can do the same job 😅 > > But in the end it's still a really, really good article. **@iyxan23** · 7 upvotes > my cpu went up to 100% as I'm scrolling the page lol **@przemekhernik** · 5 upvotes > Does anyone know how to create such video visualizations? 😀 **@ajayfaul** · 3 upvotes > I'm sorry but my cpu goes high when scrolling the sites -_- ## Similar posts on daily.dev - [Don’t just attend KubeCon \+ CloudNativeCon, Merge Forward your experience\!](https://daily.dev/posts/don-t-just-attend-kubecon-cloudnativecon-merge-forward-your-experience--l0rpp73x8) · CNCF · 1 upvotes · 0 comments - [Announcing H2 2026 KCDs](https://daily.dev/posts/announcing-h2-2026-kcds-m96goajm1) · CNCF · 1 upvotes · 0 comments - [Two months of Open Community Groups](https://daily.dev/posts/two-months-of-open-community-groups-asf52zhbs) · CNCF · 0 upvotes · 0 comments --- Tags: [#javascript](https://daily.dev/tags/javascript) [View this post on daily.dev](https://daily.dev/posts/javascript-visualized-jf60glu2w) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"JavaScript Visualized","url":"https://daily.dev/posts/javascript-visualized-jf60glu2w","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/javascript-visualized-jf60glu2w"},"datePublished":"2024-03-26T03:46:01.489Z","dateModified":"2024-05-09T08:22:04.995Z","description":"This post explores the inner workings of promises in JavaScript, including the creation of promises using the `new Promise` constructor, the purpose of the...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/45fb747e951aca5c1c0942f5134bd54c?_a=AQAEufR","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/45fb747e951aca5c1c0942f5134bd54c?_a=AQAEufR","isAccessibleForFree":true,"articleSection":"Community Picks","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Community Picks","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1655817725/logos/community","url":"https://daily.dev/sources/community"},"commentCount":47,"discussionUrl":"https://daily.dev/posts/javascript-visualized-jf60glu2w","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":2478},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":47}],"keywords":"javascript","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Community Picks","item":"https://daily.dev/sources/community"},{"@type":"ListItem","position":3,"name":"JavaScript Visualized"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/javascript-visualized-jf60glu2w","comment":[{"@type":"Comment","text":"The blog website has some scrolling issues! :(","datePublished":"2024-03-26T15:31:26.488Z","url":"https://daily.dev/posts/Jf60GLU2W#c-cBNCGi08f","author":{"@type":"Person","name":"Debajyati Dey","url":"https://daily.dev/debajyatidey","image":"https://avatars.githubusercontent.com/u/127122455?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":18}},{"@type":"Comment","text":"This is a really good post that really explains the topic very well… but there is actually a problem with an asynchronous javascript in the header of the page. This script runs in the background for quite a long time and ends up running into an uncaught promise error. In addition, the site uses a million DIVs, some of which are also animated. And of course that costs a lot of CPU performance.\nWhy use a GIF when a few hundred DIVs can do the same job 😅\nBut in the end it’s still a really, really good article.","datePublished":"2024-03-27T09:35:43.008Z","url":"https://daily.dev/posts/Jf60GLU2W#c-KXCSQlgQE","author":{"@type":"Person","name":"Praetoriani","url":"https://daily.dev/praetoriani","image":"https://avatars.githubusercontent.com/u/25861571?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":12}},{"@type":"Comment","text":"my cpu went up to 100% as I’m scrolling the page lol","datePublished":"2024-03-27T01:52:35.246Z","url":"https://daily.dev/posts/Jf60GLU2W#c-xtR9FyuwE","author":{"@type":"Person","name":"Iyxan23","url":"https://daily.dev/iyxan23","image":"https://lh3.googleusercontent.com/a/ACg8ocI6YdxODV9wJ37dGIeDbcBh0YfPdN_oO3OCX9uXDVZQi5Y=s96-c"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":7}},{"@type":"Comment","text":"Does anyone know how to create such video visualizations? 😀","datePublished":"2024-03-29T07:13:24.089Z","url":"https://daily.dev/posts/Jf60GLU2W#c-eNeBbKF4e","author":{"@type":"Person","name":"Przemysław Hernik","url":"https://daily.dev/przemekhernik","image":"https://media.daily.dev/image/upload/s--7JJpra3u--/f_auto/v1711695444/avatars/avatar_UpUOqLeRNdBEeh4AReqrJ"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":5}},{"@type":"Comment","text":"I’m sorry but my cpu goes high when scrolling the sites -_-","datePublished":"2024-03-27T03:55:12.997Z","url":"https://daily.dev/posts/Jf60GLU2W#c-yRVfjDeyC","author":{"@type":"Person","name":"M Fajar Maulana","url":"https://daily.dev/ajayfaul","image":"https://avatars.githubusercontent.com/u/32429908?v=4"},"interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":3}}]} ```